As I've said before, Facebook can continue to push users around with design changes and even privacy and get away with it. My opinion is that if you don't like it, don't use it. However they're in one of those unique situations where they have such a critical mass and consumer investment that no one is going anywhere fast. This is why they'll last far longer than MySpace.
However, the people you can't push around are the advertisers, those that fund the social network.
Facebook recently decided to make some significant changes to official page structures, and were fortunately forced to revoke them immediately due to backlash. And at some point in the indeterminable future, they're going to adjust the width of tabs. Nearly every brand will be caught out, and the agencies will be forced to fix them on their on dollar.
While Facebook is happy to deal with those willing to spend some solid dosh, everyone caught in between aren't getting the love. And they may just think about asking their clients to invest elsewhere....